What am i doing bad? I play well and i can't climb!

I climbed to silver 5 earlier this season before demoting since i wasn't really ready yet i think, returned down to bronze 5 on tilt . Now, it seems like every time im on a climb the matchmaking give me uncarriable games until im back to bronze 4 0 lp and then i get a win... and the infinte cycle of hellish holding back return... Also, if i get just one decent teamate, i'm able to climb almost unopposed. One of my friends is the same rank as me and when we play together, we always win except for one game where we had an afk. I'm not saying riot put me intently whith trolls and afk, tho i think the fact that when im on a climb being put as the carry player make me much more likely to get some of these because im put with people with bad winrates. (and there's probably a reason)

Also, im sure i deserve to be higher since in flex i am bronze 3 with 52% win rate (probably better because there is less horrible players in this since some are higher ranks) Also, i bought 2 smurfs and on both of them i placed silver 3 while being 5/5 ( on one of them i went 6/4 in flex and got the same rank)

These last games i tend to have really good kda with around 5-8 cs per min and usually am one of the best on team except for the games im too tilted to play right. Though, even while playing so well, and playing my highest win rate champs, there is too much fucking games i cant carry because my teammates are clueless and i have no way to work with them like i should. This is not fucking right, on my opinion, there should be variations on lp gains according to the work of the player for victory.

my playstyle right now is kind of, farming the most i can while trading trying to not lose cs and avoiding taking damage when the enemy is out of position. i ward my bushes and i play near them. i focus on pushing objectives, i try to roam as fast as possible when my minions are pushed and one of my lane is behind, i try to take cs in jungle or in lanes in between for not losing gold, when there is some kind of grouping appearing i try to join the group while repelling the too much pushed lanes before. i try to engage if im fighter or tank, i try to attack from backline if im mage or adc, i taken opportunities when im assassin, i never surrender or flame. Though even if i try to carry the hardest i fucking can, most of time, it's not even sufficient for the win... >:(

please, please, give me all the tips needed, i just fucking want to reach gold+ someday. :(